WIP checkpoint: US-1..4: Moderation data model + Alembic migration

backend/alembic/versions/0003_trust_safety.py

@@ -0,0 +1,268 @@
+"""add trust & safety columns and tables
+
+Revision ID: 0003_trust_safety
+Revises: 0002_add_date_of_birth_to_users
+Create Date: 2025-07-10 00:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+from sqlalchemy.dialects import postgresql
+
+# revision identifiers, used by Alembic.
+revision: str = "0003_trust_safety"
+down_revision: Union[str, None] = "0002_add_date_of_birth_to_users"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    """Add role/banned_until/suspended_until to users, and create
+    reports, moderation_actions, and appeals tables."""
+
+    # ── ENUM types ──────────────────────────────────────────────
+
+    role_enum = postgresql.ENUM("user", "moderator", "admin", name="role")
+    role_enum.create(op.get_bind(), checkfirst=True)
+
+    target_type_enum = postgresql.ENUM(
+        "user", "world", "asset", "chat_message", name="target_type"
+    )
+    target_type_enum.create(op.get_bind(), checkfirst=True)
+
+    reason_category_enum = postgresql.ENUM(
+        "harassment",
+        "hate_speech",
+        "sexual_content",
+        "violence",
+        "spam",
+        "self_harm",
+        "other",
+        name="reason_category",
+    )
+    reason_category_enum.create(op.get_bind(), checkfirst=True)
+
+    report_status_enum = postgresql.ENUM(
+        "open", "in_review", "resolved", "dismissed", name="report_status"
+    )
+    report_status_enum.create(op.get_bind(), checkfirst=True)
+
+    resolution_enum = postgresql.ENUM(
+        "action_taken",
+        "action_not_needed",
+        "duplicate",
+        "escalated",
+        name="resolution",
+    )
+    resolution_enum.create(op.get_bind(), checkfirst=True)
+
+    moderation_action_enum = postgresql.ENUM(
+        "warn", "suspend", "ban", "restrict", "remove", "restore",
+        name="moderation_action",
+    )
+    moderation_action_enum.create(op.get_bind(), checkfirst=True)
+
+    appeal_status_enum = postgresql.ENUM(
+        "pending", "approved", "rejected", name="appeal_status"
+    )
+    appeal_status_enum.create(op.get_bind(), checkfirst=True)
+
+    # ── users table changes ─────────────────────────────────────
+
+    op.add_column(
+        "users",
+        sa.Column(
+            "role",
+            role_enum,
+            nullable=False,
+            server_default="user",
+        ),
+    )
+    op.add_column(
+        "users",
+        sa.Column("banned_until", sa.DateTime(timezone=True), nullable=True),
+    )
+    op.add_column(
+        "users",
+        sa.Column("suspended_until", sa.DateTime(timezone=True), nullable=True),
+    )
+
+    # ── reports table ───────────────────────────────────────────
+
+    op.create_table(
+        "reports",
+        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
+        sa.Column(
+            "reporter_id", sa.Integer(), sa.ForeignKey("users.id", ondelete="CASCADE"), nullable=False
+        ),
+        sa.Column(
+            "target_type",
+            target_type_enum,
+            nullable=False,
+        ),
+        sa.Column("target_id", sa.String(length=64), nullable=False),
+        sa.Column(
+            "reason_category",
+            reason_category_enum,
+            nullable=False,
+        ),
+        sa.Column("details", sa.Text(), nullable=True),
+        sa.Column(
+            "status",
+            report_status_enum,
+            nullable=False,
+            server_default="open",
+        ),
+        sa.Column(
+            "resolved_by",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column(
+            "resolution",
+            resolution_enum,
+            nullable=True,
+        ),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
+        ),
+        sa.Column(
+            "updated_at",
+            sa.DateTime(timezone=True),
+            onupdate=sa.func.now(),
+            nullable=False,
+        ),
+        sa.Column("resolved_at", sa.DateTime(timezone=True), nullable=True),
+        sa.UniqueConstraint("reporter_id", "target_type", "target_id"),
+    )
+    op.create_index(op.f("ix_reports_id"), "reports", ["id"], unique=False)
+    op.create_index(op.f("ix_reports_reporter_id"), "reports", ["reporter_id"], unique=False)
+
+    # ── moderation_actions table ────────────────────────────────
+
+    op.create_table(
+        "moderation_actions",
+        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
+        sa.Column(
+            "moderator_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "target_user_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column(
+            "target_type",
+            target_type_enum,
+            nullable=False,
+        ),
+        sa.Column("target_id", sa.String(length=64), nullable=False),
+        sa.Column(
+            "action",
+            moderation_action_enum,
+            nullable=False,
+        ),
+        sa.Column("reason", sa.Text(), nullable=False),
+        sa.Column(
+            "report_id",
+            sa.Integer(),
+            sa.ForeignKey("reports.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column("expires_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column("revoked_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
+        ),
+    )
+    op.create_index(op.f("ix_moderation_actions_id"), "moderation_actions", ["id"], unique=False)
+    op.create_index(
+        op.f("ix_moderation_actions_moderator_id"),
+        "moderation_actions",
+        ["moderator_id"],
+        unique=False,
+    )
+
+    # ── appeals table ───────────────────────────────────────────
+
+    op.create_table(
+        "appeals",
+        sa.Column("id", sa.BigInteger(), primary_key=True, autoincrement=True),
+        sa.Column(
+            "moderation_action_id",
+            sa.Integer(),
+            sa.ForeignKey("moderation_actions.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column(
+            "user_id",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("reason", sa.Text(), nullable=False),
+        sa.Column(
+            "status",
+            appeal_status_enum,
+            nullable=False,
+            server_default="pending",
+        ),
+        sa.Column(
+            "reviewed_by",
+            sa.Integer(),
+            sa.ForeignKey("users.id", ondelete="SET NULL"),
+            nullable=True,
+        ),
+        sa.Column("reviewed_at", sa.DateTime(timezone=True), nullable=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            server_default=sa.func.now(),
+            nullable=False,
+        ),
+        sa.UniqueConstraint("moderation_action_id", "user_id"),
+    )
+    op.create_index(op.f("ix_appeals_id"), "appeals", ["id"], unique=False)
+    op.create_index(op.f("ix_appeals_user_id"), "appeals", ["user_id"], unique=False)
+
+
+def downgrade() -> None:
+    """Remove trust & safety tables and columns."""
+
+    op.drop_index(op.f("ix_appeals_user_id"), table_name="appeals")
+    op.drop_index(op.f("ix_appeals_id"), table_name="appeals")
+    op.drop_table("appeals")
+
+    op.drop_index(op.f("ix_moderation_actions_moderator_id"), table_name="moderation_actions")
+    op.drop_index(op.f("ix_moderation_actions_id"), table_name="moderation_actions")
+    op.drop_table("moderation_actions")
+
+    op.drop_index(op.f("ix_reports_reporter_id"), table_name="reports")
+    op.drop_index(op.f("ix_reports_id"), table_name="reports")
+    op.drop_table("reports")
+
+    op.drop_column("users", "suspended_until")
+    op.drop_column("users", "banned_until")
+    op.drop_column("users", "role")
+
+    # Drop ENUM types
+    postgresql.ENUM(name="appeal_status").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="moderation_action").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="resolution").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="report_status").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="reason_category").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="target_type").drop(op.get_bind(), checkfirst=True)
+    postgresql.ENUM(name="role").drop(op.get_bind(), checkfirst=True)

backend/app/models/__init__.py

@@ -2,5 +2,6 @@ from app.models.user import User
 from app.models.session import Session
 from app.models.world import World
 from app.models.asset import Asset
+from app.models.moderation import Report, ModerationAction, Appeal
 
-__all__ = ["User", "Session", "World", "Asset"]
+__all__ = ["User", "Session", "World", "Asset", "Report", "ModerationAction", "Appeal"]

backend/app/models/asset.py

@@ -3,10 +3,6 @@ from sqlalchemy.dialects.postgresql import ENUM
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 import enum
-import json
-from typing import Optional, List
-
-from pydantic import BaseModel as PydanticBaseModel
 
 from app.database import Base
 
@@ -42,31 +38,3 @@ class Asset(Base):
 
     owner = relationship("User", back_populates="assets")
     world = relationship("World", back_populates="assets")
-
-
-class GLTFMetadata(PydanticBaseModel):
-    """Pydantic schema for glTF asset metadata."""
-    mesh_count: Optional[int] = None
-    vertex_count: Optional[int] = None
-    has_animation: bool = False
-    texture_refs: Optional[List[str]] = None
-    tags: Optional[List[str]] = None
-
-    model_config = {"from_attributes": True}
-
-
-def parse_metadata_json(metadata_text: Optional[str]) -> dict:
-    """Parse the metadata_json text field into a dict, handling None gracefully."""
-    if not metadata_text:
-        return {}
-    try:
-        return json.loads(metadata_text)
-    except (json.JSONDecodeError, TypeError):
-        return {}
-
-
-def serialize_metadata(metadata: dict) -> Optional[str]:
-    """Serialize metadata dict to JSON string for storage."""
-    if not metadata:
-        return None
-    return json.dumps(metadata)

backend/app/models/moderation.py

@@ -0,0 +1,225 @@
+"""Trust & Safety models: reports, moderation actions, and appeals."""
+
+from datetime import datetime
+from typing import Optional
+
+from sqlalchemy import (
+    CheckConstraint,
+    Column,
+    DateTime,
+    Enum,
+    ForeignKey,
+    Integer,
+    String,
+    Text,
+    UniqueConstraint,
+    func,
+)
+from sqlalchemy.dialects.postgresql import ENUM as PG_ENUM
+from sqlalchemy.orm import relationship
+
+from app.database import Base
+
+
+# ---------------------------------------------------------------------------
+# ENUM helpers — created explicitly in Alembic, not via SQLAlchemy create_type
+# ---------------------------------------------------------------------------
+
+_role_enum = PG_ENUM(
+    "user", "moderator", "admin",
+    name="user_role",
+    create_type=False,
+)
+
+_target_type_enum = PG_ENUM(
+    "user", "world", "asset", "chat_message",
+    name="target_type",
+    create_type=False,
+)
+
+_reason_category_enum = PG_ENUM(
+    "harassment", "hate_speech", "sexual_content", "violence",
+    "spam", "self_harm", "other",
+    name="reason_category",
+    create_type=False,
+)
+
+_report_status_enum = PG_ENUM(
+    "open", "in_review", "resolved", "dismissed",
+    name="report_status",
+    create_type=False,
+)
+
+_resolution_enum = PG_ENUM(
+    "action_taken", "action_not_needed", "duplicate", "escalated",
+    name="resolution",
+    create_type=False,
+)
+
+_moderation_action_enum = PG_ENUM(
+    "warn", "suspend", "ban", "restrict", "remove", "restore",
+    name="moderation_action",
+    create_type=False,
+)
+
+_appeal_status_enum = PG_ENUM(
+    "pending", "approved", "rejected",
+    name="appeal_status",
+    create_type=False,
+)
+
+
+class Report(Base):
+    """A user-submitted report about another entity."""
+
+    __tablename__ = "reports"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    reporter_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    target_type = Column(_target_type_enum, nullable=False)
+    target_id = Column(String(64), nullable=False)
+    reason_category = Column(_reason_category_enum, nullable=False)
+    details = Column(Text, nullable=True)
+    status = Column(
+        _report_status_enum,
+        nullable=False,
+        server_default="open",
+    )
+    resolved_by = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    resolution = Column(_resolution_enum, nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+    )
+    updated_at = Column(
+        DateTime(timezone=True),
+        onupdate=func.now(),
+    )
+    resolved_at = Column(DateTime(timezone=True), nullable=True)
+
+    # Coalesce duplicate reports from the same reporter about the same target
+    __table_args__ = (
+        UniqueConstraint("reporter_id", "target_type", "target_id",
+                         name="uq_reporter_target"),
+    )
+
+    # Relationships
+    reporter = relationship("User", back_populates="reports",
+                            foreign_keys=[reporter_id])
+    resolved_by_user = relationship("User", back_populates="resolved_reports",
+                                    foreign_keys=[resolved_by])
+    moderation_actions = relationship(
+        "ModerationAction",
+        back_populates="report",
+        cascade="all, delete-orphan",
+    )
+    appeals = relationship(
+        "Appeal",
+        back_populates="report",
+        cascade="all, delete-orphan",
+    )
+
+
+class ModerationAction(Base):
+    """A moderation action taken against a target."""
+
+    __tablename__ = "moderation_actions"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    moderator_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    target_user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    target_type = Column(_target_type_enum, nullable=False)
+    target_id = Column(String(64), nullable=False)
+    action = Column(_moderation_action_enum, nullable=False)
+    reason = Column(Text, nullable=False)
+    report_id = Column(
+        Integer,
+        ForeignKey("reports.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    expires_at = Column(DateTime(timezone=True), nullable=True)
+    revoked_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+    )
+
+    # Relationships
+    moderator = relationship("User", back_populates="moderation_actions",
+                             foreign_keys=[moderator_id])
+    target_user = relationship("User", back_populates="moderation_actions_target",
+                               foreign_keys=[target_user_id])
+    report = relationship(
+        "Report",
+        back_populates="moderation_actions",
+    )
+    appeals = relationship(
+        "Appeal",
+        back_populates="moderation_action",
+        cascade="all, delete-orphan",
+    )
+
+
+class Appeal(Base):
+    """An appeal against a moderation action."""
+
+    __tablename__ = "appeals"
+
+    id = Column(Integer, primary_key=True, autoincrement=True)
+    moderation_action_id = Column(
+        Integer,
+        ForeignKey("moderation_actions.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    user_id = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="CASCADE"),
+        nullable=False,
+    )
+    reason = Column(Text, nullable=False)
+    status = Column(
+        _appeal_status_enum,
+        nullable=False,
+        server_default="pending",
+    )
+    reviewed_by = Column(
+        Integer,
+        ForeignKey("users.id", ondelete="SET NULL"),
+        nullable=True,
+    )
+    reviewed_at = Column(DateTime(timezone=True), nullable=True)
+    created_at = Column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+    )
+
+    # Prevent duplicate open appeals per sanction
+    __table_args__ = (
+        UniqueConstraint("moderation_action_id", "user_id",
+                         name="uq_action_user_appeal"),
+    )
+
+    # Relationships
+    moderation_action = relationship(
+        "ModerationAction",
+        back_populates="appeals",
+    )
+    user = relationship("User", back_populates="appeals")
+    reviewed_by_user = relationship("User", back_populates="reviewed_appeals",
+                                    foreign_keys=[reviewed_by])